I was asked - but only asked - about the rate when I used the Little League rate in Stockholm, Sweden.
"What is this rate?"
"Little League Baseball. I'm the parent of a Little League player."
"Ah, okay."
That was the extent of it.
Because Mom qualifies for Silver (60+), I had to do a little bit of dancing on my machine but finally got her booked for the Thanksgiving weekend in Williamsburg at that rate. I warned her to make sure she packs her driving license, not just because she's driving, but because they'll definitely want to check that one.
She and I shared a room in Virginia this spring and the Sleep Inn did ask for her ID to qualify for the rate.
Smarter Travel/Smarter Living rate never was questioned. AARP has not been questioned (Mom used it once), but I don't yet qualify for 50+ so I don't book with that code.
Little League, as far as I can tell, only requires that you have interest in the sport, not that you are a parent or relative of a player.